1. Field of the Invention
The invention relates generally to snow removal tools, and more specifically, to a device useful to remove accumulated snow from a sloped roof of a building by subdividing a section of snow and then pulling the section over the edge of the roof.
2. Prior Art
Snow accumulated on a roof of a building can cause various problems. For example, heat transferred from the interior through the roof can partially melt snow on the roof, the runoff water refreezing at the eaves as icicles that can fall away. Ice built up at the eaves can get underneath roofing shingles, damaging the roof and possibly leaking water into the building. Accumulated snow and ice can suddenly cascade off the roof, especially a steep roof. Very heavy accumulations of snow on a roof in some cases can cause structural damage to a building.
It is therefore desirable to remove accumulated snow from a sloped roof before problems occur. A device for removing snow from a roof is disclosed in U.S. Pat. No. 3,773,375--Nehls, having a rectangular-shaped blade transversely fixed to the end of an elongated handle. A person on the ground manipulates the blade with the handle so that the blade digs into the snow at an elevation of the roof above the eaves. The operator pulls on the handle to urge the snow below the blade downwardly over the eaves.
A problem with this type of device is that, especially for heavy wet snow, there is a significant coefficient of static friction to be overcome. The snow near the surface tends to pack the snow near the roof. The snow in front of the blade adheres not only to the roof, but also to the adjacent snow that is not in the direct path of the blade. Pulling on the tool engages a downwardly spreading swath of snow. Instead of sliding down the slope of the roof in front of the blade, the snow tends to pack and to pile up in front of the blade, making it difficult to engage the blade closely along the roof surface. Packing of the snow produces even more static friction, exacerbating the problem.
It would be advantageous to structure a snow removal device for roofs and other surfaces that can overcome problems with static friction that result from the tendency of snow to pack and stick together.